Adjust windowRect of plugins for root frame scrolling.

third_party/WebKit/Source/web/WebPluginContainerImpl.cpp

Index: third_party/WebKit/Source/web/WebPluginContainerImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebPluginContainerImpl.cpp b/third_party/WebKit/Source/web/WebPluginContainerImpl.cpp
index 60ab35cf439ce584894150ffa595f198ca372518..33505ad2f21ee57e393179ca34817102d632a8e2 100644
--- a/third_party/WebKit/Source/web/WebPluginContainerImpl.cpp
+++ b/third_party/WebKit/Source/web/WebPluginContainerImpl.cpp
@@ -974,8 +974,9 @@ void WebPluginContainerImpl::computeClipRectsForPlugin(
     LayoutRect unclippedAbsoluteRect(frameRectInOwnerElementSpace);
     box->mapRectToPaintInvalidationBacking(rootView, unclippedAbsoluteRect, nullptr);
 
-    // The frameRect is already in absolute space.
+    // The frameRect is already in absolute space, except for scrolling of the root frame.
     windowRect = frameRect();
+    windowRect.moveBy(roundedIntPoint(-rootView->viewRect().location()));
 
     clippedLocalRect = enclosingIntRect(unclippedAbsoluteRect);
     unclippedIntLocalRect = clippedLocalRect;
@@ -988,7 +989,7 @@ void WebPluginContainerImpl::computeClipRectsForPlugin(
 
 void WebPluginContainerImpl::calculateGeometry(IntRect& windowRect, IntRect& clipRect, IntRect& unobscuredRect, Vector<IntRect>& cutOutRects)
 {
-    // document().layoutView() can be 0 when we receive messages from the
+    // document().layoutView() can be null when we receive messages from the
     // plugins while we are destroying a frame.
     // FIXME: Can we just check m_element->document().isActive() ?
     if (m_element->layoutObject()->document().layoutView()) {